Calibration adjuster for repulsion vane type instruments



Jan. 12, 1965 D. F. ROERTY 3,165,695

CALIBRATION ADJUSTER FOR REPULSION VANE TYPE INSTRUMENTS Filed Dec. 22, 1960 WITNESSES INVENTOR Dennis E Roerry )4 {MK B y w A! United States Patent 3,165,695 CALERATHGN ADJUSTER F01. REPULSEQN JANE TYPE EJSTRUMENTS Dennis F. Roerty, Jersey City, NJ, assignor to Westinghouse Electric (Iorporation, East Pittsburgh, 1221., a corporation of Pennsylvania Filed Dec. 22, 1966, Ser. No. 77,694 1 Claim. (Cl. 324-147) This invention relates generally to iron vane instruments and more specifically to a calibrating adjustment means for a book type repulsion iron vane instrument. It is an improvement over application Serial No. 27,034, filed by Veron S. Thomander, May 5, 1960, now Patent No. 3,074,016, dated January 15, 1963, entitled Adjustment for Calibration of Instrument and assigned to the same assignee as is this application.

An object of this invention is to provide an improved means for moving the stationary vane to effect calibration of the instrument.

A further object of this invention is to provide a support for the movable vane such that stresses due to movement thereof in calibration, clamping, etc. will not affect the magnetic characteristics of the adjustable vane.

A further ob'ect is to provide such an adjustment which is easily actuated without disturbing other portions of the instrument.

Other objects will be apparent from the specification and claims and from the drawings in which:

FIGURE 1 is a top plan view of a portion of an iron vane book type instrument embodying the invention;

FIG. 2 is an elevational view, partly in section, of the instrument shown in FIG. 1; and,

FIG. 3 is a detailed view of the stationary adjustable vane and its support.

Referring to the drawings by characters of reference, the numeral 1 designates generally an instrument for indicating an electrical quantity having a supporting structure 2 of non-magnetic material such as plastic. The structure 2 is provided with a main or base portion 4 which has a circularly cylindrical extending portion 6 extending rearwardly and forward extending posts 7 which support a bridging member 8 and which are provided with outwardly extending apertured mounting lugs 9. The cylindrical portion 6 intermediate its outer end wall 16 and the main portion 4, is provided with a sector-like aperture 11 having longitudinally extending side walls 12 and 14. The base or main portion 4 is provided with an aperture 16 opening outwardly through the upper end wall 18 of the base portion 4 and opening into the sector-like aperture 11. A shaft 20 is pivotally supported by taut bands 22 and 24 for rotational movement about its longitudinal axis. The detailed construction of the taut band suspension devices 26 and 28 are illustrated more fully in copending application Serial No. 761,899, filed September 18, 1958, by Veron S. Thomander for Instrument Mechanisms, now Patent No. 3,111,623, dated November 19, 1963, and assigned to the same assignee as is this application.

The lower taut band suspension device 28 is carried by the end wall 10 concentrically of the circular cylindrical extension 6. Likewise, the taut band suspension device 26 is carried by the bridge member 8 which is secured by screws 32 to the top surface of the posts 7.

The usual pointer or indicating needle 34 is carried at the upper end of the shaft 20 in a suitable manner such as by the forward tower 35 and cooperates with suitable indicia 36 to indicate the rotational position of the shaft 20.

The rotation of the shaft is determined by the degree of magnetization of a pair of relatively movable plate-like members or vanes 37 and 38 which are located Within the sector-like aperture 11. The magnetic vane 37 is pref- 3,165,695 Patented Jan. 12, 1965 ice erably rectangular as illustrated and extends longitudinally of the aperture 11. It is provided with a tab 39 along a longitudinal edge thereof which is formed to at least partially encompass the shaft 20 and suitably cemented thereto as by an epoxy resin. The magnetic vane 33 is preferably of substantially the sameshape and size as is the vane 37 but is provided with a cut-away portion 40 to provide clearance for the rear tower 41.

The vane 38 is cemented or otherwise secured to an elongated non-magnetic plate-like member 42 which has a wedge-shape protuberance 44 extending downwardly from its rearward end surface 46 and which is received within'a slot 48 in the upper surface of the lower end wall 10. The elongated member 42 lies along the surface of the aperture wall 12 and terminates in an arcuate end surface 50 which is arcuate about the knife edge of the wedge-shape protuberance 44. This surface 50 preferably extends slightly beyond or forwardly of the bottom surface 52 of the aperture 16; In order that the member 42 may be maintained in an adjusted or set position, a V-shaped clamp 54 is provided. This clamp is like the clamp 37 of the copending application Serial No. 27,034, Patent 3,074,016, and has one leg 55 seating against a tapered wall 56 of an aperture 57 in the end wall 52 as is more fully illustrated in the just mentioned copending application. A second perpendicularly extending leg =8 overlies the outer surface of the elongated member 42. A screw 60 is threaded into the bottom wall 52 and is tightened to cam the leg 55 of the V-shaped clamp 54 along the surface 56 to cause the leg 58 to engage the outer surface of the elongated member 42 and clamp it to the wall 12 whereby the member is frictionally held in its adjusted position. Movement of the elongated calibrating arm 42 is accomplished by means of an actuating arm 62 which extends upward and forwardly from a laterally extending extension of the elongated member 42. The actuating arm 62 can be moved either by a persons finger or by a tool (not shown) which fits over the projection 62 and extends forwardly of the structure 2. If the tool fits tightly on the projection 62, the length thereof will determine the closeness with which the elongated member 42 may be placed in its pivoted adjusted position.

As set forth in the copending application, Serial No. 27,034, Patent 3,074,016, pivotal movement of the stationary vane 38 in a direction parallel to wall 12 and which is also'parallel to the vane 37 in the most counterclockwise position of the shaft 20 controls the degree of congruency of the vanes 37 and 38 to control the amount of repulsion therebetween for any degree of magnetization of the vanes 37 and 38 and thereby the calibration of the instrument. I

The vanes 37 and 38 are magnetized by means of a coil 66 wound about a spool 68 which has a hollow cylindrical interior 70 which telescopes over the cylindrical extension 6. When energized the winding 66 causes flux proportional in magnitude to the degree of energization thereof to flow longitudinally through the relatively movable vanes 37 and 38. Since both of these vanes are temporariiy energized in the same polarity they tend to repel one another thereby causing the vanes 37 to rotate the shaft 26 in a clockwise direction as viewed in FIG. 1. The clockwise rotation of the shaft 20 is opposed by the torsion force exerted by the taut bands 22 and 24 and the rotational position of the shaft 20 will be dependent upon the degree of energization of the coil 66. The position of the shaft 20 is indicated by the pointer 34 and the indicia 36.

Although the invention has been described with reference to a certain embodiment thereof, numerous modifications are possible and it is desired to cover all modifications falling within the scope of the invention.

oneness What is claimed and is desired to be secured by United States Letters Patent is as follows:

In an instrument of the character described, a supportingmember having a base portion and a circularly cylindrical portion extending outwardly of said base portion and having an end wall spaced from said base portion, said cylindrical portion intermediate said end wall and said base portion being provided with a sector-like aperture opening outwardiy through the peripheral Wall of said cylindrical portion, a shaft having a portion located within said aperture and coaxial of said cylindrical portion, means pivotally supporting said shaft on said supporting member, a first plate-like member of magnetic material carried by said shaft portion and extending outwardly therefrom, a second plate-like member of mag netic material, an elongated plate-like member of nonmagnetic material having a longitudinally projecting protuberance at one end thereof and having a laterally projecting protuberance at the opposite end thereof, said lateral protuberance having an operating finger extending outwardly therefrom in a direction generally longitudinal of said elongated member, said one end of said elongated member being positioned within said aperture with said protuberance engaging said cylindrical portion end wall and with said elongated member lying in a plane substantially parallel to the plane of said first magnetic member when said shaft is in a first rotative position, means securing said second magnetic member to the surface of said elongated member adjacent said first magnetic member, the end surface at said opposite end of said elongated member being arcuate about said protuberance, and a clamp carried by said supporting member and overlying said end surface for clampingly securing said elongated member intadjusted pivotal position to determine the degree of congruence of said magnetic members.

References Qited in the file of this patent UNITED STATES PATENTS 2,456,667 Alter Dec. 21, 1948 2,481,276 Andersson Sept. 6, 1949 2,865,001 Millar Dec. 16, 1958 2,875,409 Lamb Feb. 24, 1959 3,074,016 Thomander Jan. 15, 1963 

